The German steel giant in talks to collaborate with Tata Steel was hit by a "massive" cyber attack earlier this year

I'm City A.M.'s deputy night editor and books editor of the City Pages section. Previously I reported on industrials, covering mining energy, utilities and military, and prior to that I reported on vice "sin"-dustries (think alcohol, tobacco and gambling) and the leisure sector.

Follow Francesca

ThyssenKrupp is one of the world's largest steelmakers (Source: Getty)

Francesca Washtell

The German steel giant in talks to merge with Tata Steel today said it was hit by a “massive” cyber attack earlier this year.

ThyssenKrupp said technical trade secrets were stolen from the steel production and manufacturing plant design division, as well as other areas yet to be determined.

The attackers were based in Southeast Asia, according to ThyssenKrupp, and had engaged its database with “organised, highly professional hacker activities”.

The cyber attack was discovered by the company’s internal security team in April and traced back to February.

ThyssenKrupp's disclosure follows an attack last week on routers owned by German telecoms giant Deutche Telekom, that caused an outage for nearly 1m customers.

German press reported the security breach targeted ThyssenKrupp’s Hagen Hohenlimburg specialty steel plant in western Germany, though the company declined to identify which locations were infected or the scale of the intellectual property losses.